Prosthetic valve for transluminal delivery

ABSTRACT

A prosthetic valve assembly for use in replacing a deficient native valve comprises a replacement valve supported on an expandable valve support. If desired, one or more anchors may be used. The valve support, which entirely supports the valve annulus, valve leaflets, and valve commissure points, is configured to be collapsible for transluminal delivery and expandable to contact the anatomical annulus of the native valve when the assembly is properly positioned. Portions of the valve support may expand to a preset diameter to maintain coaptivity of the replacement valve and to prevent occlusion of the coronary ostia. A radial restraint, comprising a wire, thread or cuff, may be used to ensure expansion does not exceed the preset diameter. The valve support may optionally comprise a drug elution component. The anchor engages the lumen wall when expanded and prevents substantial migration of the valve assembly when positioned in place. The prosthetic valve assembly is compressible about a catheter, and restrained from expanding by an outer sheath. The catheter may be inserted inside a lumen within the body, such as the femoral artery, and delivered to a desired location, such as the heart. A blood pump may be inserted into the catheter to ensure continued blood flow across the implantation site during implantation procedure. When the outer sheath is retracted, the prosthetic valve assembly expands to an expanded position such that the valve and valve support expand at the implantation site and the anchor engages the lumen wall. Insertion of the catheter may optionally be performed over a transseptally delivered guidewire that has been externalized through the arterial vasculature. Such a guidewire provide dual venous and arterial access to the implantation site and allows additional manipulation of the implantation site after arterial implantation of the prosthetic valve. Additional expansion stents may be delivered by venous access to the valve.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a continuation-in-part of U.S. Ser.No. 10/412,634 filed on Apr. 10, 2003, which is (1) acontinuation-in-part of U.S. Ser. No. 10/130,355 filed on May 17, 2002,which is the U.S. national phase under § 371 of InternationalApplication No. PCT/FR00/03176, filed on Nov. 15, 2000, which waspublished in a language other than English and which claimed priorityfrom French Application No. 99/14462 filed on Nov. 17, 1999, now FrenchPatent No. 2,800,984, and (2) also a continuation-in-part ofInternational Application No. PCT/FR01/03258 filed on Oct. 19, 2001,which was published in a language other than English and which claimedpriority from French Application No. 00/14028 filed on Oct. 31, 2000,now French Patent No. 2,815,844.

FIELD OF THE INVENTION

[0002] The present invention relates to a prosthetic cardiac valve andrelated deployment system that can be delivered percutaneously throughthe vasculature, and a method for delivering same.

BACKGROUND OF THE INVENTION

[0003] Currently, the replacement of a deficient cardiac valve is oftenperformed by opening the thorax, placing the patient underextracorporeal circulation or peripheral aorto-venous heart assistance,temporarily stopping the heart, surgically opening the heart, excisingthe deficient valve, and then implanting a prosthetic valve in itsplace. U.S. Pat. No. 4,106,129 to Carpentier describes a bioprostheticheart valve with compliant orifice ring for surgical implantation. Thisprocedure generally requires prolonged patient hospitalization, as wellas extensive and often painful recovery. It also presents advancedcomplexities and significant costs.

[0004] To address the risks associated with open heart implantation,devices and methods for replacing a cardiac valve by a less invasivemeans have been contemplated. For example, French Patent Application No.99 14462 illustrates a technique and a device for the ablation of adeficient heart valve by percutaneous route, with a peripheral valvularapproach. International Application (PCT) Nos. WO 93/01768 and WO97/28807, as well as U.S. Pat. No. 5,814,097 to Sterman et al., U.S.Pat. No. 5,370,685 to Stevens, and U.S. Pat. No. 5,545,214 to Stevensillustrate techniques that are not very invasive as well as instrumentsfor implementation of these techniques.

[0005] U.S. Pat. No. 3,671,979 to Moulopoulos and U.S. Pat. No.4,056,854 to Boretos describe a catheter-mounted artificial heart valvefor implantation in close proximity to a defective heart valve. Both ofthese prostheses are temporary in nature and require continuedconnection to the catheter for subsequent repositioning or removal ofthe valve prosthesis, or for subsequent valve activation.

[0006] With regard to the positioning of a replacement heart valve,attaching this valve on a support with a structure in the form of a wireor network of wires, currently called a stent, has been proposed. Thisstent support can be contracted radially in such a way that it can beintroduced into the body of the patient percutaneously by means of acatheter, and it can be deployed so as to be radially expanded once itis positioned at the desired target site. U.S. Pat. No. 3,657,744 toErsek discloses a cylindrical, stent-supported, tri-leaflet, tissue,heart valve that can be delivered through a portion of the vasculatureusing an elongate tool. The stent is mounted onto the expansion toolprior to delivery to the target location where the stent and valve areexpanded into place. More recently, U.S. Pat. No. 5,411,552 to Andersenalso illustrates a technique of this type. In the Andersen patent, astent-supported tissue valve is deliverable percutaneously to the nativeheart valve site for deployment using a balloon or other expandingdevice. Efforts have been made to develop a stent-supported valve thatis self-expandable, using memory materials such as Nitinol.

[0007] The stent-supported systems designed for the positioning of aheart valve introduce uncertainties of varying degree with regard tominimizing migration from the target valve site. A cardiac valve that isnot adequately anchored in place to resist the forces of the constantlychanging vessel wall diameter, and turbulent blood flow therethrough,may dislodge itself, or otherwise become ineffective. In particular, theknown stents do not appear to be suited to sites in which the cardiacwall widens on either proximally and/or distally of the valve annulussitus. Furthermore, the native cardiac ring remaining after ablation ofthe native valve can hinder the positioning of these stents. These knownsystems also in certain cases create problems related to the sealingquality of the replacement valve. In effect, the existing cardiac ringcan have a surface that is to varying degrees irregular and calcified,which not only lessens the quality of the support of the stent againstthis ring but also acts as the source of leaks between the valve andthis ring. Also, these systems can no longer be moved at all afterdeployment of the support, even if their position is not optimal.Furthermore, inflating a balloon on a stented valve as described byAndersen may traumatize the valve, especially if the valve is made froma fragile material as a living or former living tissue.

[0008] Also, the existing techniques are however considered notcompletely satisfactory and capable of being improved. In particular,some of these techniques have the problem of involving in any caseputting the patient under extracorporeal circulation or peripheralaorto-venous heart assistance and temporary stopping of the heart; theyare difficult to put into practice; they do not allow precise control ofthe diameter according to which the natural valve is cut, in view of thelater calibration of the prosthetic valve; they lead to risks ofdiffusion of natural valve fragments, often calcified, into theorganism, which can lead to an embolism, as well as to risks ofperforation of the aortic or cardiac wall; they moreover induce risks ofacute reflux of blood during ablation of the natural valve and risk ofobstruction of blood flow during implantation of the device with aballoon expandable stent for example.

SUMMARY OF THE INVENTION

[0009] The object of the present invention is to transluminally providea prosthetic valve assembly that includes features for preventingsubstantial migration of the prosthetic valve assembly once delivered toa desired location within a body. The present invention aims to remedythese significant problems. Another objective of the invention is toprovide a support at the time of positioning of the replacement valvethat makes it possible to eliminate the problem caused by the nativevalve sheets, which are naturally calcified, thickened and indurated, orby the residues of the valve sheets after valve resection. Yet anotherobjective of the invention is to provide a support making possiblecomplete sealing of the replacement valve, even in case of an existingcardiac ring which has a surface which is to varying degrees irregularand/or to varying degrees calcified. Another objective of the inventionis to have a device that can adapt itself to the local anatomy (i.e.varying diameters of the ring, the subannular zone, the sino-tubularjunction) and maintain a known diameter of the valve prosthesis tooptimize function and durability. The invention also has the objectiveof providing a support whose position can be adapted and/or corrected ifnecessary at the time of implantation.

[0010] The present invention is a prosthesis comprising a tissue valvesupported on a self-expandable stent in the form of a wire or aplurality of wires that can be contracted radially in order to makepossible the introduction of the support-valve assembly into the body ofthe patient by means of a catheter, and which can be deployed in orderto allow this structure to engage the wall of the site where the valveis to be deployed. In one embodiment, the valve is supported entirelywithin a central, self-expandable, band. The prosthetic valve assemblyalso includes proximal and distal anchors. In one embodiment, theanchors comprise discrete self-expandable bands connected to the centralband so that the entire assembly expands in unison into place to conformmore naturally to the anatomy.

[0011] The valve can be made from a biological material, such as ananimal or human valve or tissue, or from a synthetic material, such as apolymer, and includes an annulus, leaflets and commissure points. Thevalve is attached to the valve support band with, for example, a suture.The suture can be a biologically compatible thread, plastic, metal oradhesive, such as cyanoacrylate. In one embodiment, the valve supportband is made from a single wire bent in a zigzag manner to form acylinder. Alternatively, the valve support band can be made from aplurality of wires interwoven with one another. The wire can be madefrom stainless steel, silver, tantalum, gold, titanium, or any suitabletissue or biologically compatible plastic, such as ePTFE or Teflon. Thevalve support band may have a loop at its ends so that the valve supportband can be attached to an upper anchor band at its upper end, and alower anchor band at its lower end. The link can be made from, forexample, stainless steel, silver, tantalum, gold, titanium, any suitableplastic material, or suture.

[0012] The prosthetic valve assembly is compressible about its centeraxis such that its diameter can be decreased from an expanded positionto a compressed position. The prosthetic valve assembly may be loadedonto a catheter in its compressed position, and so held in place. Onceloaded onto the catheter and secured in the compressed position, theprosthetic valve assembly can be transluminally delivered to a desiredlocation within a body, such as a deficient valve within the heart. Onceproperly positioned within the body, the catheter can be manipulated torelease the prosthetic valve assembly and permit it to into its expandedposition. In one embodiment, the catheter includes adjustment hooks suchthat the prosthetic valve assembly may be partially released andexpanded within the body and moved or otherwise adjusted to a finaldesired location. At the final desired location, the prosthetic valveassembly may be totally released from the catheter and expanded to itsfully expanded position. Once the prosthetic valve assembly is fullyreleased from the catheter and expanded, the catheter may be removedfrom the body.

[0013] Other embodiments are contemplated. In one such alternativeembodiment, this structure comprises an axial valve support portion thathas a structure in the form of a wire or in the form of a network ofwires suitable for receiving the replacement valve mounted on it, andsuitable for supporting the cardiac ring remaining after the removal ofthe deficient native valve. The embodiment may further comprise at leastone axial wedging portion, that has a structure in the form of a wire orin the form of a network of wires that is distinct from the structure ofsaid axial valve support portion, and of which at least a part has, whendeployed a diameter greater or smaller than that of said deployed axialvalve support portion, such that this axial wedging portion or anchor issuitable for supporting the wall bordering said existing cardiac ring.The embodiment preferably further comprises at least one wire forconnecting the two portions, the wire or wires being connected at pointsto these portions in such a way as not to obstruct the deployment ofsaid axial portions according to their respective diameters. Theembodiment thus provides a support in the form of at least two axialportions that are individualized with respect to one another with regardto their structure, and that are connected in a localized manner by atleast one wire; where this wire or these wires do not obstruct thevariable deployment of the axial portion with the valve and of the axialwedging portion(s) or anchors. The anchors may be positioned distally orproximally.

[0014] The presence of a structure in the form of a wire or in the formof a network of wires in the axial valve support portion makes possiblea perfect assembly of this valve with this structure, and the shape aswell as the diameter of this axial portion can be adapted for supportingthe existing cardiac ring under the best conditions. In particular, thisaxial valve support portion can have a radial force of expansion suchthat it pushes back (“impacts”) the valve sheets that are naturallycalcified or the residues of the valve sheets after valve resection ontoor into the underlying tissues, so that these elements do not constitutea hindrance to the positioning of the replacement valve and also allowfor a greater orifice area. This structure also makes it possible tosupport an optional anchoring means and/or optional sealing means forsealing the space between the existing cardiac ring and the replacementvalve, as indicated below.

[0015] The configuration of each anchor portion can be adapted forsupporting the cardiac wall situated at the approach to the existingcardiac ring under the best conditions. In particular, this anchorportion can have a tubular shape with a constant diameter greater thanthat of the axial valve support portion, or the form of a truncated conewhose diameter increases with distance from the axial valve supportportion. By attaching at least one anchor portion to the axial valvesupport portion, the prosthetic valve assembly assumes a non-cylindricalor toroidal configuration. This non-cylindrical configuration providesan increased radial expansion force and increased diameter at both endsof the prosthetic valve assembly that may tighten the fit between thevalve assembly and surrounding tissue structures. The tighter fit from anon-cylindrical configuration can favorably increase the anchoring andsealing characteristics of the prosthesis. The axial valve supportportion itself may be non-cylindrical as well.

[0016] Preferably, the tubular support has an axial valve supportportion in the form of at least two parts, of which at least one issuitable for supporting the valve and of which at least another issuitable for pushing back the native valve sheets or the residues of thenative valve sheets after valve resection, into or onto the adjacenttissue in order to make this region able to receive the tubular support.This axial valve support portion eliminates the problem generated bythese valve or cardiac ring elements at the time of positioning of thereplacement valve. The radial force of this axial valve support portion,by impacting all or part of the valvular tissue or in the wall or itsvicinity in effect ensures a more regular surface more capable ofreceiving the valve support axis. It also ensures a better connectionwith the wall while reducing the risk of peri-prosthetic leakage.Furthermore, such a structure permits the valve to maintain a diameterwithin a preset range to ensure substantial coaptivity and avoidsignificant leakage.

[0017] The particular method of maintaining the valve diameter within apreset range described above relates to the general concept ofcontrolling the expanded diameter of the prosthesis. The diameterattained by a portion of the prosthesis is a function of the radialinward forces and the radial expansion forces acting upon that portionof the prosthesis. A portion of the prosthesis will reach its finaldiameter when the net sum of these forces is equal to zero. Thus,controlling the diameter of the prosthesis can be addressed byaddressing the radial expansion force, the radial inward forces, or acombination of both. Changes to the radial expansion force generallyoccur in a diameter-dependent manner and can occur extrinsically orintrinsically. Resisting further expansion can occur extrinsically byusing structural restraints that oppose the intrinsic radial expansionforce of the prosthesis, or intrinsically by changing the expansionforce so that it does not expand beyond a preset diameter. The firstway, referred to previously, relates to controlling expansionextrinsically to a preset diameter to ensure coaptivity. In oneembodiment configured to control diameter, a maximum diameter of atleast a portion of the support structure may be ensured by a radialrestraint provided along at least a portion of circumference of thesupport structure. The radial restraint may comprise a wire, thread orcuff engaging the support structure. The restraint may be attached tothe support structure by knots, sutures or adhesives, or may beintegrally formed with the support structure. The radial restraints mayalso be integrally formed with the support structure during themanufacturing of the support structure. The configuration of the radialrestraint would depend upon the restraining forces necessary and theparticular stent structure used for the prosthesis. A radial restraintcomprising a mechanical stop system is also contemplated. A mechanicalstop system uses the inverse relationship between the circumference ofthe support structure and the length of the support structure. As thesupport structure radially expands, the longitudinal length of thesupport structure will generally contract or compress as the wires ofthe support structure having a generally longitudinal orientation changeto a circumferential orientation during radial expansion. By limitingthe distance by which the support structure can compress in alongitudinal direction, or the angle to which the support structurewires reorient, radial expansion in turn can be limited to a maximumdiameter. The radial restraint may comprise a plurality of protrusionson the support structure where the protrusions abut or form a mechanicalstop against another portion of the support structure when the supportstructure is expanded to the desired diameter.

[0018] In an embodiment configured to control the expanded diameterintrinsically for a portion of the support, the radial expansion forceof the valve support may be configured to apply up to a preset diameter.This can be achieved by the use of the shape memory effect of certainmetal alloys like nickel titanium or Nitinol. When Nitinol material isexposed to body heat, it will expand from a compressed diameter to itsoriginal diameter. As the Nitinol prosthesis expands, it will exert aradial expansion force that decreases as the prosthesis expands closerto its original diameter, reaching a zero radial expansion force whenits original diameter is reached. Thus, use of a shape memory alloy suchas Nitinol is one way to provide an intrinsic radial restraint. Anon-shape memory material that is elastically deformed duringcompression will also exhibit diameter-related expansion forces whenallowed to return to its original shape.

[0019] Although both shape memory and non-shape memory based materialmay provide diameter-dependent expansion forces that reach zero uponattaining their original shapes, the degree of force exerted can befurther modified by altering the thickness of the wire or structure usedto configure the support or prosthesis. The prosthesis may be configuredwith thicker wires to provide a greater expansion force to resist, forexample, greater radial inward forces located at the native valve site,but the greater expansion force will still reduce to zero upon theprosthesis attaining its preset diameter. Changes to the wire thicknessneed not occur uniformly throughout a support or a prosthesis. Wirethickness can vary between different circumferences of a support orprosthesis, or between straight portions and bends of the wirestructure.

[0020] The other way of controlling diameter previously mentioned is toalter or resist the radial inward or recoil forces acting upon thesupport or prosthesis. Recoil forces refer to any radially inward forceacting upon the valve assembly that prevents the valve support frommaintaining a desired expanded diameter. Recoil forces include but arenot limited to radially inward forces exerted by the surrounding tissueand forces caused by elastic deformation of the valve support. Opposingor reducing recoil forces help to ensure deployment of the supportstructure to the desired diameter.

[0021] Means for substantially minimizing recoil are also contemplated.Such means may include a feature, such as a mechanical stop, integralwith the support structure to limit recoil. By forming an interferencefit between the mechanical stop and another portion of the supportstructure when the support structure is expanded to its preset diameter,the support structure can resist collapse to a smaller diameter andresist further expansion beyond the preset diameter. The interferencefit may comprise an intercalating teeth configuration or a latchmechanism. Alternatively, a separate stent may be applied to the lumenof the cardiac ring to further push aside the native valve leaflets orvalve remnants by plastically deforming a portion of the prosthesis.This separate stent may be placed in addition to the support structureand may overlap at least a portion of the support structure. Byoverlapping a portion of the support structure, the separate stent canreduce any recoil force acting on the support structure. It is alsocontemplated that this separate stent might be applied to the nativelumen before the introduction of the valve prosthesis described herein.Another alternative is to plastically deform the valve assembly diameterbeyond its yield point so that the prosthesis does not return to itsprevious diameter.

[0022] At portions of the prosthesis where the control of the expansionforce against surrounding tissue is desired, the various methods forcontrolling diameter can be adapted to provide the desired control ofexpansion force. Portions of the prosthesis may include areas used foranchoring and sealing such as the axial wedging portions previouslydescribed.

[0023] Specifically, in order to support the valve, the axial valvesupport portion can have a part in the form of an undulating wire withlarge-amplitude undulations, and a part in the form of an undulatingwire with small-amplitude undulations, adjacent to said part with largeamplitude undulations, having a relatively greater radial force in orderto make it possible to push said valvular tissue against or into thewall of the passage. Preferably, the support according to one embodimentof the present invention has two axial wedging portions, one connectedto an axial end of said valve support portion and the other to the otheraxial end of this same valve support portion. These two axial wedgingportions thus make it possible to wedge the support on both sides of theexisting cardiac ring, and consequently make possible complete wedgingof the support in two opposite directions with respect to the treatedsite. If necessary, for example, in the case in which the passage withthe valve has an aneurysm, the support according to the invention has:an axial holding portion, suitable for supporting in the deployed statethe wall of the passage, and connecting wires such as the aforementionedconnecting wires, connecting said axial valve support portion and saidaxial holding portion, these wires having a length such that the axialholding portion is situated after implantation a distance away from theaxial valve support portion. This distance allows said axial holdingportion to rest against a region of the wall of the passage not relatedto a possible defect which may be present at the approach to the valve,particularly an aneurysm. The length of the connecting wires can also becalculated in order to prevent the axial holding portion from cominginto contact with the ostia of the coronary arteries. The aforementionedaxial portions (valve support, wedging, holding portions) can have astructure in the form of an undulating wire, in zigzag form, orpreferably a structure in diamond-shaped mesh form, the mesh parts beingjuxtaposed in the direction of the circumference of these portions. Thislast structure allows a suitable radial force making it possible toensure complete resting of said portions against the wall that receivesthem.

[0024] As previously mentioned, the support according to the inventioncan be produced from a metal that can be plastically deformed. Theinstrument for positioning of the support then includes a balloon whichhas an axial portion with a predetermined diameter, adapted forrealizing the deployment of said axial valve support portion, and atleast one axial portion shaped so as to have, in the inflated state, agreater cross section than that of the passage to be treated, in such away as to produce the expansion of the axial wedging portion placed onit until this axial wedging portion encounters the wall which it isintended to engage. The support according to this embodiment of thepresent invention can also be produced from a material that can beelastically deformed or even a material with shape memory, such asNitinol, which can be contracted radially at a temperature differentfrom that of the body of the patient and which regains its originalshape when its temperature approaches or reaches that of the body of thepatient.

[0025] Alternatively, the support may be made from a shape memorymaterial that can be plastically deformed, or may be partially made froma shape memory material and partially made from a material that can beplastically deformed. With this embodiment, the support can be brought,by shape memory or plastic deformation, from a state of contraction to astable intermediate state of deployment between the state of contractionand the state of total deployment, and then by plastic deformation orshape memory respectively, from said intermediate state of deployment tosaid state of total deployment. In said intermediate state ofdeployment, the support is preferably configured such that it remainsmobile with respect to the site to be treated. The support may thus bebrought to the site to be treated and then deployed to its intermediatestate; its position can then possibly be adapted and/or corrected, andthen the support be brought to its state of total deployment. Oneexample of a shape memory material that can be plastically deformed maybe a nickel-titanium alloy of the type called “martensitic Nitinol” thatcan undergo plastic deformation by means of a balloon. By using aballoon to expand and stress the alloy beyond its yield point, plasticdeformation can occur. Plastic deformation by a balloon of a portion ofthe prosthesis that has already undergone self-expansion can also beused to compensate for any recoil that occurs.

[0026] Advantageously, the support according to the invention has someanchoring means suitable for insertion into the wall of the site to betreated, and is shaped in such a way as to be mobile between an inactiveposition, in which it does not obstruct the introduction of the supportinto the body of the patient, and an active position, in which it isinserted into the wall of the site to be treated. Substantially completeimmobilization of the support at the site is thus obtained. Inparticular, this anchoring means can be in the form of needles and canbe mounted on the support between retracted positions and radiallyprojected positions. Advantageously, the axial valve support portionhas, at the site of its exterior surface, a sealing means shaped in sucha way as to absorb the surface irregularities that might exist at ornear the existing cardiac ring. This sealing means can consist of aperipheral shell made from a compressible material such as polyester ortissue identical to the valve or a peripheral shell delimiting a chamberand having a radially expandable structure, this chamber being capableof receiving an inflating fluid suitable for solidifying after apredetermined delay following the introduction into said chamber. Thissealing means can also include a material that can be applied betweenthe existing cardiac ring and the axial valve support portion, thismaterial being capable of solidifying after a predetermined delayfollowing this application. Specifically, in this case, this material iscapable of heat activation, for example, by means of a laser, throughthe balloon, or capable of activation by emission of light ofpredetermined frequency, for example, by means of an ultraviolet laser,through the balloon. Said sealing means can also be present in the formof an inflatable insert with a spool-shaped cross section in theinflated state, which can be inserted between the existing cardiac ringand the axial valve support portion, Said spool shape allows this insertto conform to the best extent possible to the adjacent irregularstructures and to provide a better seal.

[0027] In one embodiment of the invention, a drug-eluting component iscontemplated. This component comprises a surface coating or matrixbonding to at least a portion of support structure. Drug elution is wellknown to those in the art. Potential drugs may include but are notlimited to antibiotics, cellular anti-proliferative andanti-thrombogenic drugs.

[0028] An assembly and method for removing the native valve is alsocontemplated. In particular, the invention has the objective ofproviding a device that gives complete satisfaction with regard to theexeresis and replacement of the valve, while allowing one to operatewithout opening of the thorax, stopping of the heart and/or opening ofthe heart, and preventing any diffusion into the circulatory system offragments of the removed valve. In one embodiment, the assemblycomprises: (a) an elongated support element; (b) a first set ofelongated blades arranged around the circumference of said elongatedelement and connected in a pivoting manner to the elongated element atthe site of their proximal longitudinal ends, each blade having a sharpedge at the site of its distal longitudinal end and configured to pivotwith respect to the elongated element between a folded up (retracted)position, in which they are near the wall of the elongated element insuch a way that they do not stand in the way of the introduction andsliding of the device in the body channel in which the valve is located,in particular in the aorta, and an opened out (protracted) position, inwhich these blades are spread out in the form of a corolla in such a waythat their sharp edges are placed in extension of one another and thusconstitute a sharp circular edge; (c) a second set of blades arrangedconsecutively to said first series of blades in the distal direction;the blades of this second set have a structure identical to that of theblades of said first set, wherein the blades of this second series areconnected to the elongated element by their distal longitudinal ends andwherein each has a sharp edge at the site of its proximal longitudinalend; (d) means making it possible to bring the blades of said first andsecond set from their retracted position to their protracted position;(e) means for permitting axial movement of the sets of blades axiallyrelative to one another between a spaced position in which one set ofblades can be placed axially on one side of the natural valve while theother set of blades is placed axially on the other side of this valve,and a proximate position in which the sharp circular edges of the twosets of blades may be brought into mutual contact for excising thenatural valve.

[0029] A method of using this assembly comprises the steps ofintroducing the assembly percutaneously into said body channel anddelivering the assembly to a position where the first and second sets ofblades are spaced on opposite sides of the natural valve using the meansof identification. The method may further comprise putting in place asystem of peripheral aorto-venous heart assistance, extracorporealcirculation or a blood pump through the center of the delivery systemfor pumping blood, in the case of an aortic valve replacement, from theleft ventricle (proximal to the aortic valve) to the aorta (distal tothe aortic valve) in order to facilitate the flow of the blood, for thepurpose of preventing stagnation of the blood in the heart. Oneembodiment of a blood flow pump is described further below. After theassembly is positioned in place, the method further comprises spreadingthe blades of the two sets of blades out; then bringing the two setscloser together to excise the valve. The configuration of these bladesmakes it possible to execute this cutting in a single operation,minimizing the generation of fragments that can be diffused into thecirculatory system. This configuration moreover makes possible precisecontrol of the diameter according to which the natural valve is cut, inview of later calibration of the prosthetic valve. The blades may thenbe retracted for placement of the prosthetic valve.

[0030] The prosthetic valve may be deployed discretely from theassembly, in which case the method may comprise removing the assemblyand then separately deploying the prosthetic valve. Preferably however,the assembly comprises a proximal prosthetic valve having an expandablesupport structure that may occupy a contracted position near the wall ofsaid elongated element for transmission through the body channel, and anexpanded position to replace the natural cardiac valve.

[0031] After excising the natural valve, the method further comprisessliding the assembly axially in the distal direction in order to bringthe prosthetic valve to the desired site in the channel, and thenexpanding the prosthetic valve support into place. The assembly may thenbe withdrawn, recovering the excised natural valve.

[0032] Preferably, the elongated support element is a tubular catheterpermitting blood to flow through it during the excision of the naturalvalve. The cross section of the channel of this catheter can besufficient to allow the blood to flow through this channel with orwithout the help of a pump. Continued blood flow during the excisionprocedure may limit or eliminate the need for placing the patient underextracorporeal circulation or peripheral aorto-venous heart assistance.The catheter has a lateral distal opening in order to allow the blood torejoin the body channel, for example the ascending aorta, this openingbeing arranged in such a way that the length of catheter passed throughthe blood is as short as possible. Alternatively, the catheter may havea small diameter to facilitate the introduction and delivery of theassembly in the body channel, but a small diameter might require theprovision of peripheral circulation by an external assistance systemsuch as an extracorporeal circulation system or-peripheral aorto-venousheart assistance.

[0033] Preferably, the assembly for excising the native valve includes adistal inflatable balloon, placed at the site of the exterior surface ofsaid elongated element; wherein the balloon is configured so as tooccupy a deflated position, in which it has a cross section such that itdoes not stand hinder introduction and advancement of the assemblywithin the body channel, and an expanded position. The balloon may beinflated after the positioning of the sets of blades on both sides ofthe natural valve in order to prevent reflux of the blood during theablation of the natural valve. If the elongated element is a catheter,this balloon moreover makes it possible to cause blood to flow onlythrough the catheter. Once the prosthetic valve is positioned, theballoon is deflated to re-establish the blood flow through the bodychannel.

[0034] The assembly for excising the native valve may optionally includea distal filter made of flexible material placed on the exterior surfaceof the elongated element. The filter is configured so that it can occupya retracted position or a contracted position. This filter serves tocapture possible fragments generated by the excision of the naturalvalve, for removal from the blood circulation. The assembly may includemeans for moving the sets of blades in the axial direction relative tothe balloon and/or from said filter.

[0035] The balloon and optional filter may be separate from theassembly, being mounted on an elongated support element specific tothem. In case of operation on a mitral valve, this balloon or filter maybe introduced into the aorta by a peripheral artery route, and theassembly is itself introduced into the heart by the peripheral venoussystem, up to the right atrium and then into the left atrium through theinteratrial septum, up to the site of the mitral valve. The prostheticvalve can advantageously have a frame made of a material with a shapememory, particularly a nickel-titanium alloy known as “Nitinol.” Thissame valve can have valve leaflets made of biological material(preserved animal or human valves) or synthetic material such as apolymer. When replacing an aortic valve the assembly may bealternatively introduced in a retrograde manner through a peripheralartery (femoral artery) or through a venous approach and transseptally(antegrade).

[0036] One embodiment of a system for deploying a prosthetic valve maycomprise a blood pump insertable into the lumen of a catheter tofacilitate blood flow across the native valve and implantation sitesduring the implantation procedure. When the catheter is positionedacross the implantation site, a proximal opening of the deliverycatheter is on one side of the implantation site and the lateral distalopening is on another side of the implantation site. By inserting theblood pump into the catheter lumen between the proximal and lateraldistal openings, blood flow across the native valve and implantationsites is maintained during the procedure. One embodiment of the bloodpump comprises a rotating impeller attached to a reversible motor by ashaft. When the impeller is rotated, blood flow can be created in eitherdirection along the longitudinal axis of the catheter between theproximal and lateral distal openings to provide blood flow across theimplantation site. The pump may be used during the native valve excisionstep if so carried out.

[0037] In one application of the present invention, the prosthetic valvemay be implanted by first passing a guidewire inserted peripherally, forinstance, through a vein access; transseptally from the right atrium tothe left atrium and then snaring the distal end of the guidewire andexternalizing the distal end out of the body through the arterialcirculation. This placement of the guidewire provides access to theimplantation site from both venous and arterial routes. By providingvenous access to the native valve, massive valvular regurgitation duringthe implantation procedure may be avoided by first implanting thereplacement valve and then radially pushing aside the native valveleaflets through the venous access route.

[0038] The above embodiments and methods of use are explained in moredetail below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0039]FIG. 1 is a cross-sectional side view of one embodiment of anassembly of the present invention for removing and replacing a nativeheart valve percutaneously;

[0040]FIG. 2 is a cross-section axial view of the assembly of FIG. 1taken at line II-II, shown in a closed condition;

[0041]FIG. 3 is a cross-section axial view of the assembly of FIG. 1taken at line II-II, shown in an opened condition;

[0042]FIG. 4 is a perspective schematic view of one embodiment of aprosthetic valve of the present invention;

[0043] FIGS. 5 to 9 are schematic views of the assembly of the presentinvention positioned in a heart, at the site of the valve that is to betreated, during the various successive operations by means of which thisvalve is cut out and the prosthetic valve shown in FIG. 4 deployed;

[0044]FIG. 10 is a schematic view of the prosthetic valve shown of FIG.4 shown in a deployed state;

[0045]FIG. 11 is a schematic view of an alternative embodiment of theassembly of the present invention shown treating a mitral valve;

[0046]FIG. 12 is a cross-sectional view of a section of a blade used inexcising the native valve.

[0047]FIG. 13 is a schematic view of one embodiment of the supportstructure of the prosthesis assembly of the present invention;

[0048]FIG. 14 is a cross-sectional view of the support of FIG. 13showing a heart valve supported by the central portion of the support;

[0049]FIG. 15 is an end view of the support of FIGS. 13 and 14 in thedeployed state;

[0050]FIG. 16 is an end view of the support of FIGS. 13 and 14 in thecontracted state;

[0051]FIG. 17 is a schematic view of a heart with an embodiment of thepresent inventive prosthesis shown deployed in place;

[0052]FIG. 18 is a schematic view of an alternative embodiment of thepresent invention;

[0053]FIG. 19 is schematic view of an alternative embodiment of thepresent invention;

[0054]FIG. 20 is a detail view of a part of the support structure of oneembodiment of the present invention;

[0055]FIG. 21 is a schematic view of the support of FIG. 19 shown in adeployed state;

[0056]FIG. 22 is schematic view of an alternative embodiment of thepresent invention;

[0057]FIG. 23 is a detail view of the support of FIG. 22 shown in thecontracted state;

[0058]FIG. 24 is a detail view of the support of FIG. 23 taken alongline 23-23;

[0059]FIG. 25 is a detail view of the support of FIG. 22 shown in theexpanded state;

[0060]FIG. 26 is a detail view of the support of FIG. 25 taken alongline 25-25;

[0061]FIG. 27 is a schematic view of an alternative embodiment of thepresent invention;

[0062]FIG. 28 is a detailed cross section view of the support of FIG.27;

[0063]FIG. 29 is a partial schematic view in longitudinal section of thesupport of the present invention and of a calcified cardiac ring;

[0064]FIG. 30 is a schematic view of an alternative to the support ofFIG. 29;

[0065]FIG. 31 is a schematic view of an alternative to the support ofFIG. 29;

[0066]FIGS. 32 and 33 are schematic views of an alternative to thesupport of FIG. 29;

[0067]FIG. 34 is a schematic cross-sectional view of a ballooncorresponding to the support structure of FIGS. 19 to 21;

[0068]FIG. 35 is a schematic longitudinal sectional view of analternative embodiment of the balloon of FIG. 34;

[0069]FIG. 36 is a schematic view of a heart with an embodiment of thepresent inventive prosthesis shown deployed in place;

[0070]FIG. 37 is a perspective view of one embodiment of a prostheticvalve assembly of the present invention;

[0071]FIG. 38 is a side view of the prosthetic valve assembly of FIG.37;

[0072]FIG. 39 is a perspective view of one embodiment of the prostheticvalve assembly of FIG. 37;

[0073]FIG. 40 is a perspective view of an alternative embodiment of theprosthetic valve assembly with a sheath around the valve;

[0074]FIG. 41A is a perspective view of a distal portion of a catheterassembly for use in deploying the prosthetic valve assembly describedherein;

[0075]FIG. 41B is a perspective view of a proximal portion of thecatheter assembly of FIG. 41A;

[0076]FIG. 42 is a perspective view of the distal portion of thecatheter assembly of FIG. 41A;

[0077]FIGS. 43 through 45 are perspective views of the catheter assemblyof FIG. 41A showing deployment of a prosthesis assembly in sequence;

[0078]FIGS. 46 and 47 are perspective views of the catheter assembly ofFIG. 41A showing deployment of an alternative prosthesis assembly;

[0079]FIG. 48 is a perspective view of the alternative prosthesisassembly shown in FIGS. 46 and 47.

[0080]FIG. 49 is a perspective view of an alternative embodiment of theprosthetic valve assembly of FIG. 37 showing a distal anchor;

[0081]FIG. 50 is side view of an impeller and impeller housing of oneembodiment of the blood pump;

[0082]FIG. 51 is a side view of a catheter with catheter openings thatallow blood flow by the impeller;

[0083]FIG. 52 is a side view of the catheter with the impeller in placeand blood flow depicted by arrows;

[0084]FIG. 53 depicts another embodiment of the invention with aseparate blood pump catheter relative to the prosthesis delivery system;

[0085]FIG. 54 illustrates the embodiment shown in FIG. 16 with the bloodpump in place and blood flow shown by arrows;

[0086]FIG. 55 depicts one embodiment of the present invention comprisingloop elements released from a delivery catheter after withdrawal of anouter sheath;

[0087]FIGS. 56A and 56B represent one embodiment of the radial restraintcomprising a wire interwoven into the support structure;

[0088]FIG. 57 depicts another embodiment of the invention wherein tworadial restraints of different size are attached to different portionsof the support structure;

[0089]FIG. 58 represents one embodiment of the radial restraintcomprising a cuff-type restraint;

[0090]FIG. 59 is a schematic view of a wire bend with a symmetricallyreduced diameter;

[0091]FIG. 60 is a schematic view of an alternative embodiment of a wirebend with an asymmetrically reduced diameter;

[0092]FIG. 61 is a schematic view of one embodiment of the implantationprocedure for the prosthetic valve where the distal end of atransseptally placed guidewire has been externalized from the arterialcirculation;

[0093]FIG. 62 is a schematic view of a balloon catheter passed over theguidewire of FIG. 61 to dilate the native valve;

[0094]FIG. 63 is a schematic view showing the deployment of a prostheticvalve by an arterial approach over the guidewire of FIG. 62;

[0095]FIG. 64 is a schematic view showing a balloon catheter passed overthe guidewire of FIG. 63 from a venous approach and placed opposite thestented native valve for additional ablation and/or securing of thelower portion of the stent;

[0096]FIG. 65 is a schematic view showing how the stent of FIG. 64remains attached to the delivery system by braces to allow fullpositioning of the stent;

[0097]FIG. 66 depicts a schematic view of another embodiment of theimplantation procedure for the prosthetic valve where a guidewire isinserted into the axillary artery and passed to the left ventricle;

[0098]FIG. 67 depicts a schematic view of a blood pump passed over theguidewire of FIG. 66;

[0099]FIG. 68 depicts a schematic view of a valve prosthesis passed overthe blood pump of FIG. 67;

[0100]FIGS. 69 and 70 depict schematic views of the deployment andattachment of the prosthesis of FIG. 68 to the vessel wall.

[0101]FIG. 71 is a photograph of a valve assembly with radial restraintsintegrally formed by laser cutting;

[0102]FIGS. 72A through 72C are schematic views of a portion of a valveassembly with different radial restraints formed by laser cutting;

[0103]FIGS. 73A through 73E are schematic views of another embodiment ofa laser cut anti-recoil feature, in various states of expansion;

[0104]FIGS. 74A and 74B are schematic views of an angular mechanicalstop for controlling diameter; and

[0105]FIGS. 75A and 75B are schematic views of an angular mechanicalstop with a latch for resisting recoil.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0106] Reference is now made to the figures wherein like parts aredesignated with like numerals throughout. FIGS. 1 to 3 represent adevice 1 for replacing a heart valve by a percutaneous route. Thisdevice comprises a tubular catheter 2 formed from three tubes 5, 6, 7engaged one inside the other and on which there are placed, from theproximal end to the distal end (considered with respect to the flow ofblood, that is to say from right to left in FIG. 1), a prosthetic valve10, two series of blades 11, 12, a balloon 13 and a filter 14. The threetubes 5, 6, 7 are mounted so that they can slide one inside the other.The interior tube 5 delimits a passage 15, the cross section of which islarge enough to allow blood to flow through it. At the proximal end, theintermediate tube 6 forms a bell housing 6 a delimiting, with theinterior tube 5, an annular cavity 17 in which the prosthetic valve 10is contained in the furled condition.

[0107]FIG. 4 shows that this valve 10 comprises an armature 20 and valveleaflets 21 mounted so that they are functionally mobile on thisarmature 20. The armature comprises a collection of wires 22, 23, 24made of shape memory material, particularly of nickel-titanium alloyknown by the name of “NITINOL;” namely, (i) a proximal end wire 22which, when the valve 10 is in the deployed state, has a roughlycircular shape; (ii) a distal end wire 23 forming three corrugations inthe axial direction, these corrugations being distributed uniformlyaround the circumference of the valve 10, and (iii) an intermediate wire24 forming longitudinal corrugations between the wires 22 and 23, thiswire 24 being connected to the latter ones via the ends of each of thesecorrugations. The valve leaflets 21 for their part are made ofbiological material (preserved human or animal valve leaflets) or ofsynthetic material, such as a polymer. The armature 20 may, when itsmaterial is cooled, be radially contracted so that the valve 10 canenter the cavity 17. When this material is heated to body temperature,this armature 20 returns to its original shape, depicted in FIG. 4, inwhich it has a diameter matched to that of a bodily vessel, particularlythe aorta, in which the native valve that is to be treated lies. Thisdiameter of the armature 20 is such that the valve 10 bears against thewall of the bodily vessel and is immobilized in the axial direction withrespect to that vessel.

[0108] Each series of blades 11, 12 comprises metal elongate blades 30and an inflatable balloon 31 situated between the catheter 2 and theseblades 30. The blades 30 have a curved profile and are arranged on thecircumference of the catheter 2, as shown in FIGS. 2, 3 and 3A. Theblades 30 of the proximal series 11 are connected pivotably to the tube6 by their proximal ends and comprise a cutting distal edge 30 a, whilethe blades 30 of the distal series 12 are connected pivotably to theexterior tube 7 by their distal ends and comprise a cutting proximaledge 30 b. The connection between the blades 30 and the respective tubes6 and 7 is achieved by welding the ends of the blades 30 together toform a ring, this ring being fixed axially to the corresponding tube 6,7 by crimping this ring onto this tube 6, 7, the pivoting of the blades30 being achieved by simple elastic deformation of these blades 30. Thispivoting can take place between a position in which the blades 30 arefurled, radially internally with respect to the catheter 2 and shown inFIGS. 1 and 2, and a position in which these blades 30 are unfurled,radially externally with respect to this catheter 2 and shown in FIG. 3.In the furled position, the blades 30 lie close to the wall of the tube6 and partially overlap each other so that they do not impede theintroduction and the sliding of the device 1 into and in the bodilyvessel in which the native valve that is to be treated lies; in saidunfurled position, the blades 30 are deployed in a corolla so that theircutting edges 30 a, 30 b are placed in the continuation of one anotherand thus constitute a circular cutting edge visible in FIG. 3.

[0109] Each balloon 31, placed between the tube 3 and the blades 30, maybe inflated from the end of the catheter 2 which emerges from thepatient, via a passage 32 formed in the tube 6. It thus, when inflated,allows the blades 30 to be brought from their furled position into theirunfurled position, and performs the reverse effect when deflated. Theaxial sliding of the tube 6 with respect to the tube 7 allows the seriesof blades 11, 12 to be moved axially toward one another, between aspaced-apart position shown in FIG. 1, and a close-together position. Inthe former of these positions, one series of blades 11 may be placedaxially on one side of the native valve while the other series of blades12 is placed axially on the other side of this valve, whereas in thelatter of these positions, the circular cutting edges of these twoseries of blades 11, 12 are brought into mutual contact and thus cutthrough the native valve in such a way as to detach it from said bodilyvessel. The tubes 5 to 7 further comprise marks (not visible in thefigures) in barium sulfate allowing the axial position of the device 1with respect to the native valve to be identified percutaneously so thateach of the two series of blades 11, 12 can be placed on one axial sideof this valve. These tubes 5 to 7 also comprise lateral distal openings(not depicted) to allow the blood to reach the bodily vessel, theseopenings being formed in such a way that the length of catheter 2through which the blood flows is as short as possible, that is to sayimmediately after the filter 14, in the distal direction.

[0110] The balloon 13 is placed on the exterior face of the tube 7,distally with respect to the series 12. This balloon 13 has an annularshape and is shaped to be able to occupy a furled position in which ithas a cross section such that it does not impede the introduction andsliding of the device 1 into and in said bodily vessel, and an unfurledposition, in which it occupies all of the space between the exteriorface of the tube 7 and the wall of said bodily vessel and, via aperipheral edge 13 a which it comprises, bears against this wall.

[0111] The filter 14 is placed distally with respect to the balloon 13,on the tube 7, to which it is axially fixed. This filter 14 is made offlexible material, for example polyester netting, and is shaped to beable to occupy a furled position in which it has a cross section suchthat it does not impede the introduction and sliding of the device 1into and in said bodily vessel, and an unfurled position in which itoccupies all of the space between the exterior face of the catheter 2and the wall of this vessel and, via a peripheral edge 14 a which itcomprises, bears against this wall.

[0112] An inflatable balloon 35 is placed between the tube 7 and thefilter 14 so as, depending on whether it is inflated or deflated, tobring the filter 14 into its respective unfurled and furled positions.In practice, as shown by FIGS. 5 to 9, the device 1 is introduced intosaid bodily vessel 50 by a percutaneous route and is slid along insidethis vessel 50 until each of the series 11, 12 of blades is placed onone side of the native valve 55 that is to be treated (FIG. 5). Thisposition is identified using the aforementioned marks. When the deviceis in this position, the proximal part of the catheter 2 is situated inthe heart, preferably in the left ventricle, while the aforementioneddistal lateral openings are placed in a peripheral arterial vessel,preferably in the ascending aorta. The balloons 13 and 35 are inflatedin such a way as to cause blood to flow only through the passage 15 andprevent blood reflux during the ablation of the valve 55. A peripheralperfusion system is set in place to facilitate this flow, as furtherdescribed below in connection with FIGS. 50 through 52. The blades 30 ofthe two series 11, 12 are then deployed (FIG. 6) by inflating theballoons 31, then these two series 11, 12 are moved closer together bysliding the tube 6 with respect to the tube 7, until the valve 55 is cutthrough (FIG. 7). The blades 30 are then returned to their furledposition by deflating the balloons 31 while at the same time remainingin their close-together position, which allows the cut-out valve 55 tobe held between them. The device 1 is then slid axially in the distaldirection so as to bring the bell housing 6 a to the appropriateposition in the vessel 50 (FIG. 8), after which the valve 10 is deployedby sliding the tube 6 with respect to the tube 5 (FIG. 9). The balloons13 and 35 are deflated then the device 1 is withdrawn and the cut-outvalve 55 is recovered (FIG. 10).

[0113]FIG. 11 shows a second embodiment of the device 1, allowingoperation on a mitral valve 56. The same reference numerals are used todenote the same elements or parts as the aforementioned, as long asthese elements or parts are identical or similar in both embodiments. Inthis case, the tubular catheter is replaced by a support wire 2, onwhich one of the series of blades is mounted and by a tube engaged overand able to slide along this wire, on which tube the other series ofblades is mounted; the passages for inflating the balloons 31 run alongthis support wire and this tube; the balloon 13 and the filter 14 areseparate from the device 1 and are introduced into the aorta via aperipheral arterial route, by means of a support wire 40 along which thepassages for inflating the balloons 13 and 35 run. The device 1, devoidof balloon 13 and the filter 14, is for its part introduced into theheart through the peripheral venous system, as far as the right atriumthen into the left atrium through the inter-auricular septum, as far asthe valve 56. For the remainder, the device 1 operates in the same wayas was mentioned earlier. The invention thus provides a device forreplacing a heart valve by a percutaneous route, making it possible toovercome the drawbacks of the prior techniques. Indeed the device 1 isentirely satisfactory as regards the cutting-away of the valve 55, 56,making it possible to operate without stopping the heart and making itpossible, by virtue of the filter 14, to prevent any dispersion of valvefragments 55, 56 into the circulatory system.

[0114] The above device may comprise a fourth tube, engaged on and ableto slide along the tube 7, this fourth tube comprising the balloon andthe filter mounted on it and allowing said series of blades to be movedin the axial direction independently of said balloon and/or of saidfilter; the blades may be straight as depicted in the drawing or may becurved toward the axis of the device at their end which has the cuttingedge, so as to eliminate any risk of lesion in the wall of the bodilyvessel, as shown in FIG. 12; the filter 14 may be of the self-expandingtype and normally kept in the contracted position by a sliding tube,which covers it, making the balloon 35 unnecessary.

[0115] FIGS. 13 to 16 represent tubular support 101 for positioning, bypercutaneous route, of replacement heart valve 102. The supportstructure 101 includes median portion 103, which contains valve 102, twoextreme wedging portions 104 and wires 105 for connecting these portions103 and 104. Median portion 103 also includes peripheral shell 106provided with anchoring needles 107 and shell 108 made of compressiblematerial. As is particularly apparent from FIG. 12, each of portions 103and 104 is formed with an undulating wire, and wires 105 connectpointwise the ends of the undulations of portion 103 to the end of anadjacent wave of portion 104. Portions 104, seen in expanded form, havelengths greater than the length of portion 103, so that when the ends ofthe wires respectively forming portions 103 and 104 are connected inorder to form the tubular support structure 101, the diameter of portion103 is smaller than the diameter of portions 104.

[0116] The diameter of portion 103 is such that portion 103 can, asshown by FIG. 17, support cardiac ring 110 that remains after removal ofthe deficient native valve, while portions 104 support walls 111bordering ring 110. These respective diameters are preferably such thatsaid supporting operations take place with slight radial restraint ofring 110 and walls 111. Portion 103 presents in the deployed state aconstant diameter. Portions 104 can have a constant diameter in the formof a truncated cone whose diameter increases away from portion 103. Theentire support structure 101 can be made from a material with shapememory, such as the nickel-titanium alloy known as “Nitinol.” Thismaterial allows the structure to be contracted radially, as shown inFIG. 16, at a temperature different from that of the body of the patientand to regain the original shape shown in FIGS. 14 and 15 when itstemperature approaches or reaches that of the body of the patient. Theentire support structure 101 can also be made from a material that canbe expanded using a balloon, such as from medical stainless steel (steel316 L). Valve 102 can be made of biological or synthetic tissue. It isconnected to portion 103 by sutures or by any other appropriate means ofattachment. It can also be molded on portion 103. Shell 106 may be madeof “Nitinol.” It is connected to the undulations of portion 103 atmid-amplitude, and has needles 107 at the site of its regions connectedto these undulations. Needles 107 consist of strands of metallic wirepointed at their free ends, which project radially towards the exteriorof shell 106.

[0117] This shell can take on the undulating form that can be seen inFIG. 16 in the contracted state of support 101 and the circular formwhich can be seen in FIG. 4 in the deployed state of this support 101.In its undulating form, shell 106 forms undulations 106 a projectingradially on the outside of support 101, beyond needles 107, so thatthese needles 107, in the retracted position, do not obstruct theintroduction of support 101 in a catheter or, once support 101 has beenintroduced into the heart using this catheter, do not obstruct thedeployment out of this support 1. The return of shell 106 to itscircular form brings needles 107 to a position of deployment, allowingthem to be inserted in ring 110 in order to complete the anchoring ofsupport 101. Shell 108 is attached on shell 106. Its compressiblematerial allows it to absorb the surface irregularities that might existat or near ring 110 and thus to ensure complete sealing of valve 102.

[0118]FIG. 18 shows a support structure 101 having a single portion 104connected to portion 103 by wires 105. This portion 104 is formed by twoundulating wires 114 connected together by wires 115. FIG. 19 shows asupport structure 101 that has portion 103 and portion 104 connected byconnecting wires 105. These portions 103 and 104 have diamond-shapedmesh structures, these mesh parts being juxtaposed in the direction ofthe circumference of these portions and connected together at the siteof two of their opposite angles in the direction of the circumference ofthese portions 103 and 104. Wires 105 are connected to these structuresat the site of the region of junction of two consecutive mesh parts.These mesh parts also have anchoring hooks 107 extending through themfrom one of their angles situated in the longitudinal direction ofsupport 101.

[0119]FIG. 20 illustrates, in an enlarged scale, the structure of thisportion 104 and of a part of wires 105, as cut, for example, with alaser from a cylinder of stainless steel, and after bending of sharpends 107 a of hooks 107. These hooks, in a profile view, can have theshape as shown in FIGS. 24 or 26. The structure represented in FIG. 19also has axial holding portion 120, which has a structure identical tothat of portion 104 but with a coarser mesh size, and three wires 105 ofsignificant length connecting this portion 120 to portion 103. Thesewires 105, on the side of portion 120, have a single link 105 a and onthe side of portion 103, a double link 105 b. Their number correspondsto the three junctions formed by the three valves of valve 102, whichfacilitates mounting of valve 102 on support 101 thus formed. Thesupport according to FIG. 19 is intended to be used, as appears in FIG.21, when the body passage with the valve to be replaced, in particularthe aorta, has a variation in diameter at the approach to the valve. Thelength of wires 105 connecting portions 103 and 120 is provided so thatafter implantation, portion 120 is situated in a non-dilated region ofsaid body passage, and this portion 120 is provided so as to engage thewall of the passage.

[0120]FIG. 22 shows a structure similar to that of FIG. 19 butunexpanded, except that the three wires 105 have a single wire structurebut have an undulating wire 121 ensuring additional support near portion103. This wire 121 is designed to support valve 102 with three valveleaflets. FIGS. 23 to 26 show an embodiment variant of the structure ofportions 103, 104 or 120, when this structure is equipped with hooks107. In this case, the structure has a zigzagged form, and each hook 107has two arms 107 b; each of these arms 107 b is connected to the otherarm 107 b at one end and to an arm of structure 101 at its other end.The region of junction of the two arms 107 b has bent hooking pin 107 a.

[0121]FIG. 27 shows portion 103 that has two undulating wires 125, 126extending in the vicinity of one another and secondary undulating wire127. As represented in FIG. 28, wires 125, 126 can be used to executethe insertion of valve 102 made of biological material between them andthe attachment of this valve 102 to them by means of sutures 127. FIG.29 shows a part of support 101 according to FIGS. 13 to 17 and the wayin which the compressible material constituting shell 108 can absorb thesurface irregularities possibly existing at or near ring 110, whichresult from calcifications. FIG. 30 shows support 101 whose shell 106has no compressible shell. A material can then be applied, by means ofan appropriate cannula (not represented), between ring 110 and thisshell 106, this material being able to solidify after a predetermineddelay following application.

[0122]FIG. 31 shows support 101 whose shell 106 has a cross section inthe form of a broken line, delimiting, on the exterior radial side, alower shoulder. Housed in the step formed by this shoulder and theadjacent circumferential wall is peripheral shell 108 which can beinflated by means of a catheter (not represented). This shell 108delimits a chamber and has a radially expandable structure, such that ithas in cross section, in the inflated state, two widened ends projectingon both sides of shell 106. This chamber can receive an inflating fluidthat can solidify in a predetermined delay following its introductioninto said chamber. Once this material has solidified, the inflatingcatheter is cut off.

[0123]FIGS. 32 and 33 show support 101 whose shell 106 receivesinflatable insert 108 which has a spool-shaped cross section in theinflated state; this insert 108 can be inflated by means of catheter129. Insert 108 is positioned in the uninflated state (FIG. 32) at thesites in which a space exists between shell 106 and existing cardiacring 110. Its spool shape allows this insert (cf. FIG. 33) to conform asmuch as possible to the adjacent irregular structures and to ensure abetter seal.

[0124]FIG. 34 shows balloon 130 making it possible to deploy support 101according to FIGS. 19 to 21. This balloon 130 has cylindrical portion131 whose diameter in the inflated state makes possible the expansion ofholding portion 120, a cylindrical portion 132 of lesser diameter,suitable for producing the expansion of portion 103, and portion 133 inthe form of a truncated cone, makes possible the expansion of portion104. As shown by FIG. 35, portion 132 can be limited to what is strictlynecessary for deploying portion 103, which makes it possible to produceballoon 130 in two parts instead of a single part, thus limiting thevolume of this balloon 130.

[0125]FIG. 36 shows support 101 whose median portion 103 is in two parts103 a, 103 b. Part 103 a is made of undulating wire with large-amplitudeundulations, in order to support valve 102, and part 103 b, adjacent tosaid part 103 a and connected to it by bridges 135, is made ofundulating wire with small-amplitude undulations. Due to its structure,this part 103 b presents a relatively high radial force of expansion andis intended to be placed opposite ring 110 in order to push back thenative valve sheets which are naturally calcified, thickened andindurated, or the residues of the valve sheets after valve resectionagainst or into the wall of the passage. This axial portion 103 a, 103 bthus eliminates the problem induced by these sheets or residual sheetsat the time of positioning of valve 102.

[0126] It is apparent from the preceding that one embodiment of theinvention provides a tubular support for positioning, by percutaneousroute, of a replacement heart valve, which provides, due to its portions103 and 104, complete certitude as to its maintenance of position afterimplantation. This support also makes possible a complete sealing of thereplacement valve, even in case of a cardiac ring with a surface that isto varying degrees irregular and/or calcified, and its position can beadapted and/or corrected as necessary at the time of implantation.

[0127] Referring to FIGS. 37 and 38, the present invention alsocomprises an alternative prosthetic valve assembly 310, which furthercomprises a prosthetic valve 312, a valve support band 314, distalanchor 316, and a proximal anchor 318. Valve 312 can be made from abiological material, such as one originating from an animal or human, orfrom a synthetic material, such as a polymer. Depending upon the nativevalve to be replaced, the prosthetic valve 312 comprises an annulus 322,a plurality of leaflets 324 and a plurality of commissure points 326.The leaflets 324 permit the flow of blood through the valve 312 in onlyone direction. In the preferred embodiment, the valve annulus 322 andthe commissure points 326 are all entirely supported within the centralsupport band 314. Valve 312 is attached to the valve support band 314with a plurality of sutures 328, which can be a biologically compatiblethread. The valve could also be supported on band 314 with adhesive,such as cyanoacrylate.

[0128] In one embodiment, valve 312 can be attached to, or may integralwith, a sleeve or sheath 313. The sheath is secured to the valve supportband 314 such that the outer surface of the sheath is substantially incontact with the inner surface of the valve support band 314. In suchembodiment, the sheath can be attached to the valve support band 314with sutures 328. FIG. 40 is a schematic of the concept of thisalternative embodiment. If desired, the sheath 313 can be secured to theoutside of valve support band 314 (not shown).

[0129] Referring to FIGS. 37 and 38, in one embodiment, valve supportband 314 is made from a single wire 342 configured in a zigzag manner toform a cylinder. Alternatively, valve support band 314 can be made froma plurality of wires 342 attached to one another. In either case, theband may comprise one or more tiers, each of which may comprise one ormore wires arranged in a zigzag manner, for structural stability ormanufacturing ease, or as anatomical constraints may dictate. Ifdesired, even where the central valve support 314 is manufactured havingmore than one tier, the entire valve support 314 may comprise a singlewire. Wire 342 can be made from, for example, stainless steel, silver,tantalum, gold, titanium or any suitable plastic material. Valve supportband 314 may comprise a plurality of loops 344 at opposing ends topermit attachment to valve support band 314 of anchors 316 and/or 318with a link. Loops 344 can be formed by twisting or bending the wire 342into a circular shape. Alternatively, valve support band 314 and loops344 can be formed from a single wire 342 bent in a zigzag manner, andtwisted or bent into a circular shape at each bend. The links can bemade from, for example, stainless steel, silver, tantalum, gold,titanium, any suitable plastic material, solder, thread, or suture. Theends of wire 342 can be joined together by any suitable method,including welding, gluing or crimping.

[0130] Still referring to FIGS. 37 and 38, in one embodiment, distalanchor 316 and proximal anchor 318 each comprise a discrete expandableband made from one or more wires 342 bent in a zigzag manner similar tothe central band. Distal anchor band 316 and proximal anchor band 318may comprise a plurality of loops 344 located at an end of wire 342 sothat distal anchor band 316 and proximal anchor band 318 can each beattached to valve support band 314 with a link. Loop 344 can be formedby twisting or bending the wire 342 into a circular shape. As desired,distal and/or proximal anchors 316, 318 may comprise one or more tiers,as explained before with the valve support 314. Likewise, each anchormay comprise one or more wires, regardless of the number of tiers. Asexplained above in regard to other embodiments, the distal anchor may beattached to the central valve support band 314 directly, as in FIG. 37,or spaced distally from the distal end of the valve support 314, asshown above schematically in FIGS. 18, 19, 21 and 22. In the laterinstance, one or more struts may be used to link the distal anchor bandto the valve support band, as described above.

[0131] Distal anchor band 316 has a first end 350 attached to thecentral valve band 314, and a second end 352. Similarly, proximal anchorband 318 has first attached end 354 and a second end 356. The unattachedends 352, 356 of the anchors 316, 318, respectively are free to expandin a flared manner to conform to the local anatomy. In such embodiment,the distal and proximal anchor bands 316, 318 are configured to exertsufficient radial force against the inside wall of a vessel in which itcan be inserted. Applying such radial forces provides mechanicalfixation of the prosthetic valve assembly 310, reducing migration of theprosthetic valve assembly 310 once deployed. It is contemplated,however, that the radial forces exerted by the valve support 314 may besufficient to resist more than a minimal amount of migration, thusavoiding the need for any type of anchor.

[0132] In an alternative embodiment, distal and proximal anchors maycomprise a fixation device, including barbs, hooks, or pins (not shown).Such devices may alternatively or in addition be placed on the valvesupport 314. If so desired, the prosthetic valve assembly 310 maycomprise an adhesive on the exterior thereof to adhere to the internalanatomical lumen.

[0133] Prosthetic valve assembly 310 is compressible about its centeraxis such that its diameter may be decreased from an expanded positionto a compressed position. When placed into the compressed position,valve assembly 310 may be loaded onto a catheter and transluminallydelivered to a desired location within a body, such as a blood vessel,or a defective, native heart valve. Once properly positioned within thebody the valve assembly 310 can be deployed from the compressed positionto the expanded position. FIG. 39 is a schematic of one embodiment ofthe prosthetic valve assembly described with both distal and proximalanchor bands 316, 318 while FIG. 49 is a schematic showing only a distalanchor 316.

[0134] In the preferred embodiment, the prosthetic valve assembly 310 ismade of self-expanding material, such as Nitinol. In an alternativeembodiment, the valve assembly 310 requires active expansion to deployit into place. Active expansion may be provided by an expansion devicesuch as a balloon.

[0135] As referred to above in association with other embodiments, theprosthetic valve assembly of the present invention is intended to bepercutaneously inserted and deployed using a catheter assembly.Referring to FIG. 41A, the catheter assembly 510 comprises an outersheath 512, an elongate pusher tube 514, and a central tube 518, each ofwhich are concentrically aligned and permit relative movement withrespect to each other. At a distal end of the pusher tube 514 is apusher tip 520 and one or more deployment hooks 522 for retaining theprosthesis assembly (not shown). The pusher tip 520 is sufficientlylarge so that a contracted prosthesis assembly engages the pusher tip520 in a frictional fit arrangement. Advancement of the pusher tube 514(within the outer sheath 512) in a distal direction serves to advancethe prosthesis relative to the outer sheath 512 for deployment purposes.

[0136] At a distal end of the central tube 518 is an atraumatic tip 524for facilitating the advancement of the catheter assembly 510 throughthe patient's skin and vasculature. The central tube 518 comprises acentral lumen (shown in phantom) that can accommodate a guide wire 528.In one embodiment, the central lumen is sufficiently large toaccommodate a guide wire 528 that is 0.038 inch in diameter. The guidewire can slide through the total length of the catheter form tip tohandle (‘over the wire’ catheter) or the outer sheath 512 can beconformed so as to allow for the guide wire to leave the catheter beforereaching its proximal end (‘rapid exchange’ catheter). The space betweenthe pusher tube 514 and the outer sheath 512 forms a space within whicha prosthetic valve assembly may be mounted.

[0137] Hooks 522 on the distal end of the pusher tube 514 may beconfigured in any desired arrangement, depending upon the specificfeatures of the prosthetic assembly. With regard to the prosthesisassembly of FIGS. 37 and 38, the hooks 522 preferably comprise anL-shaped arrangement to retain the prosthesis assembly axially, but notradially. With a self-expanding assembly, as the prosthesis assembly isadvanced distally beyond the distal end of the outer sheath 512, theexposed portions of the prosthesis assembly expand while the hooks 522still retain the portion of the prosthesis still housed within the outersheath 512. When the entire prosthesis assembly is advanced beyond thedistal end of the outer sheath, the entire prosthesis assembly ispermitted to expand, releasing the assembly from the hooks. FIGS. 42through 45 show the distal end of one embodiment of the catheterassembly, three of which show sequenced deployment of a valveprosthesis.

[0138]FIG. 48 shows an alternative embodiment of the valve prosthesis,where loop elements extend axially from one end of the prosthesis andare retained by the hooks 522 on pusher tube 514 during deployment.FIGS. 46 and 47 show a catheter assembly used for deploying thealternative prosthesis assembly of FIG. 48. By adding loop elements tothe prosthesis, the prosthesis may be positioned with its support andanchors fully expanded in place while permitting axial adjustment intofinal placement before releasing the prosthesis entirely from thecatheter. Referring to FIG. 55, an alternative embodiment of aself-expanding valve prosthesis and delivery system comprises loopelements 694 on prosthetic assembly 310 retained by disks 696 on pushertube 514 by outer sheath 512. When outer sheath 512 is pulled back toexpose disks 696, self-expanding loop elements 694 are then releasedfrom pusher tube 514.

[0139]FIG. 41B shows the proximal end of the catheter assembly 510 that,to a greater extent, has many conventional features. At the distal endof the pusher tube 514 is a plunger 530 for advancing and retreating thepusher tube 514 as deployment of the prosthesis assembly is desired. Asdesired, valves and flush ports proximal and distal to the valveprosthesis may be provided to permit effective and safe utilization ofthe catheter assembly 510 to deploy a prosthesis assembly.

[0140] In one embodiment, prosthetic valve assembly 310 (not shown) ismounted onto catheter 510 so that the valve assembly 310 may bedelivered to a desired location inside of a body. In such embodiment,prosthetic valve assembly 310 is placed around pusher tip 520 andcompressed radially around the tip 520. The distal end of prostheticvalve assembly 310 is positioned on the hooks 522. While in thecompressed position, outer sheath 512 is slid toward the atraumatic tip524 until it substantially covers prosthetic valve assembly 310.

[0141] To deliver prosthetic valve assembly 310 to a desired locationwithin the body, a guide wire 528 is inserted into a suitable lumen ofthe body, such as the femoral artery or vein to the right atrium, thento the left atrium through a transseptal approach, and maneuvered,utilizing conventional techniques, until the distal end of the guidewire 528 reaches the desired location. The catheter assembly 510 isinserted into the body over the guide wire 528 to the desired position.Atraumatic tip 524 facilitates advancement of the catheter assembly 510into the body. Once the desired location is reached, the outer sheath512 is retracted permitting the valve prosthesis to be released fromwithin the outer sheath 512, and expand to conform to the anatomy. Inthis partially released state, the position of prosthetic valve 310 maybe axially adjusted by moving catheter assembly 510 in the proximal ordistal direction.

[0142] It is apparent that the invention advantageously contemplates aprosthesis that may have a non-cylindrical shape, as shown in severalearlier described embodiments including but not limited to FIGS. 21,37-40, 49 and 59. This non-cylindrical shape results from controllingthe diameters at some portions of prosthetic valve assembly 310.Referring to FIG. 56A, yet another non-cylindrical prosthesis is shown.Central support band 314 comprises a diameter-restrained portion ofvalve assembly 310 attached to distal and proximal anchors 316, 318,that comprise discrete self-expandable bands capable of expanding to aflared or frusta-conical configuration. Anchors 316, 318 furtheraccentuate the non-cylindrical shape of central support band 314. FIG.56A shows one embodiment of the invention for limiting the diameter ofportions of the valve assembly 310 from excessive expansion, wherebyvalve assembly 310 further comprises a radial restraint 690 to limit thediameter of central support band 314. Radial restraint, as used herein,shall mean any feature or process for providing a desired diameter orrange of diameters, including but not limited to the selection ofmaterials or configurations for valve assembly 310 such that it does notexpand beyond a preset diameter. Controlling radial expansion to apreset diameter at central support band 314 helps maintain thecoaptivity of valve 312 and also preserves the patency of the coronaryostia by preventing central support band 314 from fully expanding to thelumen or chamber wall to cause occlusion. Restraint 690 may besufficiently flexible such that restraint 690 may contract radially withvalve assembly 310, yet in the expanded state resists stretching beyonda set limit by the radial expansion forces exerted by a self-expandingvalve assembly 310 or from a balloon catheter applied to valve assembly310. Referring to FIG. 56A and 56B, restraint 690 may take any of avariety of forms, including wires 700 of a specified length that joinportions of central support band 314. Threads may also be used forradial restraint 690. The slack or bends in the wires allow a limitedradial expansion to a maximum diameter. Once the slack is eliminated orthe bends are straightened, further radial expansion is resisted bytension created in wires 700. These wires may be soldered, welded orinterwoven to valve assembly 310. By changing the length of wire joiningportions of valve assembly 310, radial restraints of different maximumdiameters are created. For example, by using short wires to form theradial restraint, the valve support structure may expand a shorterdistance before tension forms in the short wires. If longer wires areused, the support structure may expand farther before tension developsin the longer wires.

[0143]FIG. 57 depicts central support band 314 with a radial restraint700 of a smaller diameter and another portion of the same valve assembly310 with longer lengths of wire 701 and allowing a larger maximumdiameter. The portion of valve assembly 310 with the larger diameter canbe advantageously used to allow greater dilation around cardiac ring 110and native valve sheets. The degree of resistance to expansion orrecollapse can be altered by changing the diameter of the radialrestraint or by changing the configuration of the restraint. Forexample, a cross-linked radial restraint will have a greater resistanceto both expansion and recollapse. Referring to FIG. 58, restraint 690may alternatively comprise a cuff 691 encompassing a circumference ofcentral support band 314 that resists expansion of central support band314 beyond the circumference formed by cuff 691. Cuff 691 may be made ofePTFE or any other biocompatible and flexible polymer or material as isknown to those skilled in the art. Cuff 691 may be attached to valveassembly 310 by sutures 692 or adhesives.

[0144]FIG. 71 illustrates one embodiment of the invention where radialrestraints are integrally formed as part of valve assembly 310 by usinga laser cutting manufacturing process, herein incorporated by reference.FIG. 72A depicts a schematic view of a laser-cut portion of valveassembly 310 in the unexpanded state with several radial restraints 706,708, 710. Each end of radial restraints 706, 708, 710 is integrallyformed and attached to valve assembly 310. An integrally formed radialrestraint may be stronger and may have a lower failure rate compared toradial restraints that are sutured, welded or soldered to valve assembly310. FIG. 72B depicts a shorter radial restraint 706 along onecircumference of valve assembly 310. FIG. 72C depicts another portion ofvalve assembly 310 with a longer radial restraint 708 and a cross-linkedradial restraint 710 positioned along the same circumference. Thus, thesegments of a radial restraint along a given circumference need not havethe same characteristics or size.

[0145] Another embodiment of the radial restraint comprises at least oneprotrusion extending from valve assembly 310 to provide a mechanicalstop arrangement. The mechanical stop arrangement restricts radialexpansion of valve assembly 310 by using the inverse relationshipbetween the circumference of valve assembly 310 and the length of valveassembly 310. As valve assembly 310 radially expands, the longitudinallength of valve assembly 310 may contract or compress as the diameter ofvalve assembly 310 increases, depending upon the particular structure orconfiguration used for valve assembly 310. For example, FIGS. 37, 38,56A, 57 and 71 depict embodiments of the invention wherein valveassembly 310 comprises a diamond-shaped mesh. The segments of the meshhave a generally longitudinal alignment that reorient to a morecircumferential alignment during radial expansion of valve assembly 310.By limiting the distance to which valve assembly 310 can compress in alongitudinal direction, or by restricting the amount of angularreorientation of the wires of valve assembly 310, radial expansion inturn may be controlled to a pre-set diameter. FIG. 74A shows oneembodiment of the mechanical stop arrangement comprising an angular stop730 and an abutting surface 732 on the wire structure of valve assembly310. A plurality of stops 730 and abutting surfaces 732 may be usedalong a circumference of valve assembly 310 to limit expansion to apreset diameter. Angular stop 730 may be located between two adjoiningportions of valve assembly 310 forming an angle that reduces with radialexpansion. As shown in FIGS. 74B, as valve assembly 310 radiallyexpands, angular stop 730 will come in closer proximity to surface 732and eventually abut against surface 732 to prevent further diameterexpansion of valve assembly 310. The angular size 734 of stop 730 can bechanged to provide different expansion limits. The radial size 736 ofstop 730 can also be changed to alter the strength of stop 730. Oneskilled in the art will understand that many other configurations may beused for valve assembly 310 besides a diamond-shape configuration. Forexample, FIGS. 15 and 16 depict support 101 with an undulating wirestent configuration that exhibits minimal longitudinal shortening whenexpanding. The mechanical stop arrangements described above may beadapted by those skilled in the art to the undulating wire stentconfiguration, or any other stent configuration, for controlling thediameter of the support structure or valve assembly 310.

[0146] The particular method of maintaining the valve diameter within apreset range described previously relates to the general concept ofcontrolling the expanded diameter of the prosthesis. The diameterattained by a portion of the prosthesis is a function of the radialinward forces and the radial expansion forces acting upon that portionof the prosthesis. A portion of the prosthesis will reach its finaldiameter when the net sum of these forces is equal to zero. Thus,controlling the diameter of the prosthesis can be addressed by changingthe radial expansion force, changing the radial inward forces, or acombination of both. Changes to the radial expansion force generallyoccur in a diameter-related manner and can occur extrinsically orintrinsically. Radial restraint 690, cuff 691 and mechanical stop 730 ofFIGS. 56A, 58 and 74A, respectively, are examples of extrinsic radialrestraints that can limit or resist diameter changes of prosthetic valveassembly 310 once a preset diameter is reached.

[0147] Other ways to control diameter may act intrinsically bycontrolling the expansion force so that it does not expand beyond apreset diameter. This can be achieved by the use of the shape memoryeffect of certain metal alloys like Nitinol. As previously mentioned,when a Nitinol prosthesis is exposed to body heat, it will expand from acompressed diameter to its original diameter. As the Nitinol prosthesisexpands, it will exert a radial expansion force that decreases as theprosthesis expands closer to its original diameter, reaching a zeroradial expansion force when its original diameter is reached. Thus, useof a shape memory alloy such as Nitinol is one way to provide anintrinsic radial restraint. A non-shape memory material that iselastically deformed during compression will exhibit similardiameter-dependent expansion forces when returning to its originalshape.

[0148] The other way of controlling diameter mentioned previously is toalter the radial inward or recoil forces acting upon the support orprosthesis. Recoil forces refer to any radially inward force acting uponthe valve assembly that prevents the valve support from maintaining adesired expanded diameter. Recoil forces include but are not limited toradially inward forces exerted by the surrounding tissue and forcescaused by elastic deformation of prosthetic valve assembly 310.Countering or reducing recoil forces help to ensure deployment ofprosthetic valve assembly 3,10 to the desired diameter or diameterrange, particularly at the native valve. For example, when theprosthetic valve assembly 310 of FIGS. 37, 38, 56A, 57 and 58 isdeployed, some recoil or diameter reduction may occur that can preventportions of valve assembly 310 from achieving it pre-set or desireddiameter. This recoil can be reduced by applying an expansion force,such as with a balloon, that stresses the material of valve assembly 310beyond its yield point to cause plastic or permanent deformation, ratherthan elastic or transient deformation. Similarly, balloon expansion canbe used to further expand a self-expanded portion of valve assembly 310where radially inward anatomical forces have reduced the desireddiameter of that portion. Balloon expansion of a self-expanded portionof valve assembly 310 beyond its yield point provides plasticdeformation to a larger diameter.

[0149] In addition to the use of a balloon catheter to deform valveassembly 310 beyond its yield point, other means for reducing recoil arecontemplated. In the preferred embodiment of the invention, a separatestent may be expanded against cardiac ring 110 in addition or in placeof valve assembly 310. The separate stent may further push back thenative valve sheets or residues of the resected valve and reduce therecoil force of these structures on valve assembly 310. If the separatestent is deployed against cardiac ring 110 prior to deployment of valveassembly 310, a higher radial force of expansion is exerted against ring110 without adversely affecting the restrained radial force of expansiondesired for the central support band 314 supporting valve 312.Alternatively, the separate stent may be deployed after valve assembly310 and advantageously used to reduce the recoil of valve assembly 310caused by the elastic deformation of the material used to form valveassembly 310. The separate stent may be self-expanding orballoon-expandable, or a combination thereof.

[0150] Another means for addressing recoil involves providing the radialrestraint and mechanical stop arrangements previously described with anadditional feature that forms an interference fit when the valveassembly 310 is at its preset diameter. By forming an interference fit,the radial restraint or mechanical stop will resist both furtherexpansion and recollapse from recoil. FIGS. 73A through 73E depict anembodiment of a radial restraint with a recoil-resistant configurationintegrally formed with valve assembly 310. In this embodiment, eachsegment of the radial restraint comprises a pair of protrusions 712having a proximal end 714 and a distal end 716. Proximal end 714 isintegrally formed and attached to valve assembly 310 while distal end716 is unattached. Each pair of protrusions 712 is configured so thatdistal end 716 of one protrusion 712 is in proximity to the proximal end714 of other protrusion 712 in the unexpanded state, and where distalends 716 come close together as valve assembly 310 radially expands.Distal ends 716 comprise a plurality of teeth 718 for providing aninterference fit between distal ends 716 upon contact with each other.The interference fit that is formed will resist both further radialexpansion and collapse of valve assembly 310. As mentioned earlier,collapse may result from the inherent elastic properties of thematerials used for valve assembly 310 or from radially inward forcesexerted by the tissue surrounding valve assembly 310. The interferencefit may be provided over a range of expansion, as depicted in FIGS. 72Band 72C from the self-expanded state through the extra-expanded state.This allows the inference fit to act even when a self-expanded valveassembly 310 is further expanded by a balloon catheter to anextra-expanded state as the expansion diameter is further adjusted. Thelengths of protrusions 712 will determine the amount of radial restraintprovided. Shorter protrusions 712 have distal ends 716 that contact eachother after a shorter distance of radial expansion, while longerprotrusions 712 will form an interference fit after a longer distance.

[0151]FIGS. 75A and 75B depict another embodiment of a radial restraintwith a recoil resistant feature. Angular stop 730 from FIGS. 74A and 74Bis provided with a notch 736 that forms an interference fit with a latch738 protruding from valve assembly 310 adjacent to surface 732. As valveassembly 310 expands, angular stop 730 will eventually abut against tosurface 732 to prevent further expansion. Latch 738 will also movecloser to notch 736 as valve assembly 310 expands. When the presetdiameter is reached, latch 738 forms an interference fit with notch 736that resists collapse to a smaller diameter. It is contemplated that aballoon catheter may be used to expand valve assembly 310 to the desireddiameter and to engage latch 738 to notch 736.

[0152] Although both shape memory and non-shape memory based prosthesesprovide diameter-dependent expansion forces that reach zero uponattaining their original shapes, the degree of force exerted can befurther modified by altering the thickness of the wire or structure usedto configure the support or prosthesis. A prosthesis can be configuredwith thicker wires to provide a greater expansion force to resist, forexample, greater radial inward forces located at the native valve site,but the greater expansion force will still reduce to zero upon theprosthesis attaining its preset diameter. Changes to wire thickness neednot occur uniformly throughout a support or prosthesis. Wire thicknesscan vary between different circumferences of a support or prosthesis, orbetween straight portions and bends of the wire structure. Asillustrated in FIG. 59, the decreased diameter 702 may be generallysymmetrical about the longitudinal axis of the wire. Alternatively, asin FIG. 60, the decreased diameter 704 may be asymmetrical, where thediameter reduction is greater along the lesser curvature of the wirebend or undulation relative to the longitudinal axis of the wire. Atportions of the prosthesis where the exertion of a particular expansionforce against surrounding tissue has importance over the actual diameterattained by that portion of the prosthesis, the various methods forcontrolling diameter can be adapted to provide the desired expansionforce. These portions of the prosthesis may include areas used foranchoring and sealing such as the axial wedging portions or anchorspreviously described.

[0153] Referring to FIG. 61, a method for deploying the preferredembodiment of the invention using the separate stent is provided. Themethod of deployment comprises a guidewire 640 inserted via a venousapproach 642 and passed from the right 644 to left atrium 646 through aknown transseptal approach, herein incorporated by reference. Aftertransseptal puncture, guidewire 640 is further directed from left atrium646 past the mitral valve 648 to the left ventricle 650 and through theaortic valve 652. An introducer (not shown) is inserted via an arterialapproach and a snare (not shown), such as the Amplatz GOOSE NECK® snare(Microvena, Minn.), is inserted through the introducer to grasp thedistal end of guidewire 640 and externalize guidewire 640 out of thebody through the introducer. With both ends of guidewire 640 external tothe body, access to the implantation site is available from both thevenous 642 and arterial approaches 654. In FIG. 62, aortic valve 652 ispre-dilated by a balloon catheter 656 using a well-known valvuloplastyprocedure, herein incorporated by reference. The prosthesis is thenimplanted as previously described by passing the delivery system fromeither the venous or arterial approaches. As illustrated in FIG. 63, theprosthesis 658 may be implanted using arterial approach 654 withprosthetic valve 658 implanted above the level of native valve 652. Asshown in FIG. 64, a balloon catheter 660 may be passed by venousapproach 642 for further displacement of native valve 652 and/or tofurther secure the lower stent 662 to the annulus. Hooks 664, shown inFIG. 65, connecting the delivery catheter to prosthetic valve 658 allowfull control of prosthetic valve 658 positioning until the operatorchooses to fully release and implant prosthetic valve 658. A separatestent may then be implanted by venous approach 642 at the valvular ringto further push back the native valve or valve remnants and reducerecoil forces from these structures. Passing balloon 660 by the venousapproach 642 avoids interference with superiorly located prostheticvalve 658. Implantation of replacement valve 658 by arterial approach654 prior to the ablation of the native valve 652 or valve remnants byvenous approach 642 may reduce the risks associated with massive aorticregurgitation when native valve 652 is pushed back prior to implantationof replacement valve 658. Reducing the risks of massive aorticregurgitation may provide the operator with additional time to positionreplacement valve 658.

[0154] It is further contemplated that in the preferred embodiment ofthe invention, valve assembly 310 also comprises a drug-elutingcomponent well known in the art and herein incorporated by reference.The drug-eluting component may be a surface coating or a matrix systembonded to various portions of valve assembly 310, including but notlimited to central support band 314, anchors 316 318, valve 312, loopelements 352 or wires 342. The surface coating or matrix system may havea diffusion-type, erosive-type or reservoir-based drug releasemechanism. Drugs comprising the drug-eluting component may includeantibiotics, cellular anti-proliferative and/or anti-thrombogenic drugs.Drugs, as used herein, include but are not limited to any type ofbiologically therapeutic molecule. Particular drugs may include but arenot limited to actinomycin-D, batimistat, c-myc antisense,dexamethasone, heparin, paclitaxel, taxanes, sirolimus, tacrolimus andeverolimus.

[0155] As previously mentioned, one embodiment of the system forimplanting the prosthesis and/or excising the native valve leafletscontemplates maintaining blood flow across the native valve site duringthe excision and implantation procedure. By maintaining blood flowacross the native valve, use of extracorporeal circulation or peripheralaorto-venous heart assistance and their side effects may be reduced oravoided. Major side effects of extracorporeal circulation and peripheralaorto-venous heart assistance include neurological deficits, increasedbleeding and massive air emboli. FIGS. 50 through 52 depict oneembodiment of the invention for maintaining blood perfusion during theprocedure. This embodiment comprises a blood pump 600 and an opening 602positioned in the wall of tubular catheter 2 of the excision system.When the tubular catheter 2 is positioned at the excision site, bloodpump 600 allows continued blood flow across the excision site that wouldotherwise be interrupted during the excision procedure. Blood pump 600may comprise a motor, a shaft and an impeller. Blood pump 600 isinsertable through passage 15 of tubular catheter 2. The motor isconnected to a shaft 604 that in turn is coupled to an impeller 606. Themotor is capable of rotating shaft 604, resulting in the rotation ofimpeller 606. Impeller 606 comprises a proximal end 608, a distal end610 and a plurality of fins 612 angled along the longitudinal axis ofimpeller 606, such that when impeller 606 is rotated in one direction,fins 612 are capable of moving blood from a proximal to distaldirection. When impeller 606 is rotated in the other direction, fins 612are capable of moving blood in a distal to proximal direction. Theability to rotate impeller 606 in either direction allows but is notlimited to the use of the blood pump in both anterograde and retrogradeapproaches to a heart valve. The blood pump is positioned generallyabout catheter opening 602. The blood pump has an external diameter ofabout 4-mm and the passage of the catheter has a 4-mm internal diameter.Catheter opening 602 has a longitudinal length of about 4-mm. Catheteropening 602 may comprise a plurality of openings located along acircumference of tubular catheter 2. To reduce interruption of bloodflow through tubular catheter 2 during the implantation portion of theprocedure, catheter opening 602 should preferably be about 30 mm fromthe tip of catheter 2 or distal to the bell housing 6 a. Thispositioning of catheter opening 602 reduces the risk of occlusion ofcatheter opening 602 by the replacement valve.

[0156]FIG. 50 depicts an optional feature of blood pump 600 furthercomprising an impeller housing 614 having at least one proximal housingopening 616 and at least one distal housing opening 618. Housing 614protects passage 15 of tubular catheter 2 from potential damage byrotating impeller 600. Proximal 616 and distal housing openings 618provide inflow and outflow of blood from the impeller, depending on therotation direction of impeller 600.

[0157] To reduce interruption of blood flow through catheter 2 duringthe implantation portion of the procedure, catheter opening 602 shouldpreferably be at least a distance of about 30 mm from the distal tip ofthe catheter or about distal to the bell housing 6 a to avoid occlusionof catheter opening 602 by the replacement valve.

[0158]FIGS. 53 and 54 depict an alternative embodiment, where blood pump620 is located in a second catheter 622 in the prosthesis deliverysystem. Once blood pump 620 and second catheter 622 are in position, theprosthesis delivery system 624 is slid over the separate catheter 622 toposition the prosthesis for implantation, while avoiding blockage ofblood flow in separate catheter 622. In this embodiment, the diameter ofthe delivery system is preferably about 8 mm.

[0159] One method of using the blood flow pump during the implantationof the prosthesis is now described. This procedure may be performedunder fluoroscopy and/or transesophageal echocardiography. FIG. 66 showsvascular access made through the axillary artery 666. A guidewire 668 isinserted past the aortic valve 670 and into the left ventricle 672. InFIG. 67, a blood pump 674 is inserted into a hollow catheter passed 676over guidewire 668 inside the aorta 678 and pushed into left ventricle672. Blood pump 674 is started to ensure a steady and sufficient bloodflow of about 2.5 L/min from left ventricle 672 downstream during thevalve replacement. FIG. 68 depicts valve prosthesis 680, retained on thedelivery system 682 and positioned by sliding over blood pump catheter676. Prosthesis 680 is positioned generally about the valve annulus 684and the coronary ostia 686, with the assistance of radiographic markers.As shown in FIGS. 69 and 70, the sheath 688 overlying prosthesis 680 ispulled back and prosthesis 680 is deployed as previously describedCatheter hooks 690 connecting the delivery catheter to the prostheticvalve allow full control of prosthetic valve positioning until theoperator chooses to fully release and implant the prosthetic valve.Optional anchoring hooks, described previously, may be deployedgenerally about he annulus, the ventricle and the ascending aorta.Deployment of the anchoring hooks may be enhanced by radial expansion ofa balloon catheter that further engages the hooks into the surroundingstructures. Blood pump 674 is stopped and blood pump catheter 676 isremoved. Other configurations may be adapted for replacing a valve atother site will be familiar to those skilled in the art.

[0160] The present invention may be embodied in other specific formswithout departing from its spirit or essential characteristics. Thedescribed embodiments are to be considered in all respects only asillustrative, and not restrictive and the scope of the invention is,therefore, indicated by the appended claims rather than by the foregoingdescription. For all of the embodiments described above, the steps ofthe methods need not be performed sequentially. All changes that comewithin the meaning and range of equivalency of the claims are to beembraced within their scope.

What is claimed is:
 1. A prosthetic valve assembly for use in replacinga deficient native valve, the valve assembly comprising: a valve havinga plurality of resilient leaflets; a valve support configured to becollapsible for transluminal delivery and comprising a first and asecond portion, said first portion expandable to contact the anatomicalannulus of the native valve when the assembly is properly positioned,said second portion supporting the base and the commissure points of thevalve; and a radial restraint for controlling a diameter of the secondportion.
 2. The valve assembly of claim 1, wherein the radial restraintis capable of substantially resisting expansion beyond a presetdiameter.
 3. The valve assembly of claim 1, wherein the radial restraintis capable of substantially resisting collapse below a preset diameter.4. The valve assembly of claim 1, wherein the radial restraint iscapable of substantially resisting expansion beyond a preset diameterand substantially resisting collapse below a preset diameter.
 5. Thevalve assembly of claim 1, wherein the radial restraint comprises awire.
 6. The valve assembly of claim 1, wherein the radial restraintcomprises a thread.
 7. The valve assembly of claim 1, wherein the radialrestraint comprises a mechanical stop.
 8. The valve assembly of claim 1,wherein the radial restraint comprises material from which at least aportion of the valve support is made so that the second portion does notexpand beyond a preset diameter.
 9. The valve assembly of claim 8,wherein the material comprise shape memory material.
 10. The valveassembly of claim 1, wherein the radial restraint comprises a cuff. 11.The valve assembly of claim 1, wherein the radial restraint comprises astent configured to cooperate with the valve support so as tosubstantially preclude recoil.
 12. The valve assembly of claim 1,further comprising a drug-eluting component.
 13. The valve assembly ofclaim 1, further comprising an anchor for engaging the lumen wall whenexpanded in place for preventing substantial migration of the valveassembly after deployment.
 14. The valve assembly of claim 1, whereinthe valve support comprises at least one wire.
 15. The valve assembly ofclaim 14, wherein the valve support comprises a single length of wire.16. The valve assembly of claim 14, wherein at least one portion of thesingle length of wire has a reduced thickness to decrease the radialexpansion force.
 17. A method of replacing a deficient native valvecomprising the steps of: providing a prosthetic valve assembly, theassembly comprising a valve, a valve support permitting attachmentthereto of the base and the commissures of the valve, and an anchor forengaging the lumen wall when expanded for preventing substantialmigration of the valve assembly when positioned in place; collapsing thevalve support to fit within a distally positioned sheath on a catheter;inserting a guidewire into a vascular access site; externalizing atleast a portion of the guidewire through a second vascular access site;advancing the catheter over the guidewire to the deficient native valve;deploying the valve assembly; and withdrawing the catheter, leaving thevalve assembly to function in place of the deficient native valve. 18.The method of claim 17, wherein the step of advancing the cathetercomprises advancing the catheter to the deficient native valve from thefirst vascular access site.
 19. The method of claim 17, wherein the stepof advancing the catheter comprises advancing the catheter to thedeficient native valve from the second vascular access site.
 20. Themethod of claim 17, further comprising the step of advancing a bloodpump across the deficient native valve.
 21. The method of claim 20,wherein the step of advancing the catheter comprises advancing thecatheter over the blood pump.
 22. The method of claim 20, wherein thestep of advancing the blood pump comprises inserting the blood pumpacross the first vascular access site.
 23. The method of claim 20,wherein the step of advancing the blood pump comprises inserting theblood pump across the second vascular access site.
 24. The method ofclaim 18, further comprising the steps of: advancing a stent from thesecond vascular access site to the deficient valve; deploying the stentto substantially preclude any portion of the native valve fromobstructing blood flow.
 25. The method of claim 17, wherein the valvesupport and anchor are self-expanding.
 26. The method of claim 25,further comprising the step of restraining self-expansion of the valvesupport to a preset diameter by at least one radial restraint
 27. Themethod of claim 17, wherein the valve assembly further comprises loopelements for releasably attaching the anchor to the catheter.
 28. Themethod of claim 17, wherein the catheter comprises a filter for catchingemboli or valve fragments.
 29. The method of claim 17, wherein thecatheter comprises an over-the-wire catheter.
 30. The method of claim17, wherein the catheter comprises a rapid exchange catheter.
 31. Aprosthetic valve assembly configured for endoluminal delivery to replacea deficient native valve, the valve assembly comprising an axial valvesupport portion configured to support a prosthetic valve having at leastone leaflet and to prevent substantial interference with the positioningand/or operation of the prosthetic valve by any residual components ofthe native valve, including calcified native components, said supportportion comprising at least one radial restraint at a first section ofsaid support portion to preclude expansion when deployed in situsubstantially no greater than a preset diameter to increase coaptivityof the prosthetic valve leaflets and to prevent significantregurgitation.
 32. The valve assembly of claim 31, wherein the radialrestraint is configured to reduce recoil.
 33. The valve assembly ofclaim 31, wherein the radial restraint comprises a mechanical stop. 34.The valve assembly of claim 31, wherein the support portion furthercomprises a second section configured to expand in situ for pushing theresidual native valve components against the native annulus andsurrounding tissue.
 35. The valve assembly of claim 34, wherein thesecond section is configured to expand to a diameter different from thatof the first section.
 36. The valve assembly of claim 34, wherein saidsecond section is configured to be expanded by a balloon catheter. 37.The valve assembly of claim 36, wherein said second section isconfigured to be expanded beyond its yield point in situ.
 38. The valveassembly of claim 31, further comprising a stent configured to expand insitu for pushing against the residual native valve components.
 39. Thevalve assembly of claim 38, wherein the stent is self-expanding.
 40. Thevalve assembly of claim 38, wherein the stent is configured to beexpanded by a balloon catheter.
 41. The valve assembly of claim 31,further comprising a stent configured to reduce the recoil of thesupport portion following self-expansion of the support portion.
 42. Thevalve assembly of claim 38, wherein the stent is configured to residewithin the valve support portion when deployed.
 43. The valve assemblyof claim 38, wherein the stent is configured to reside outside the valvesupport portion when deployed.
 44. The valve assembly of claim 31,further comprising at least one anchor configured to exert sufficientradial forces against the lumen wall to prevent substantial migration.45. The valve assembly of claim 31, wherein said radial restraintcomprises a wire.
 46. The valve assembly of claim 31, wherein saidradial restraint comprises a thread.
 47. The valve assembly of claim 31,wherein said radial restraint comprises a cuff.
 48. A method ofreplacing a deficient native valve comprising the steps of: providing aprosthetic valve assembly, the assembly comprising a valve, a valvesupport comprising a first valve support section permitting attachmentthereto of the base and the commissures of the valve, and a second valvesupport section configured to expand in situ to push the residual nativevalve components against the native annulus and surrounding tissue;collapsing the valve support to fit within a distally positioned sheathon a catheter; inserting a guidewire into a vascular access site;externalizing at least a portion of the guidewire through a secondvascular access site; advancing the catheter over the guidewire to thedeficient native valve; deploying the valve assembly; and withdrawingthe catheter, leaving the valve assembly to function in place of thedeficient native valve.
 49. The method of claim 48, wherein the step ofadvancing the catheter comprises advancing the catheter to the deficientnative valve from the first vascular access site.
 50. The method ofclaim 48, wherein the step of advancing the catheter comprises advancingthe catheter to the deficient native valve from the second vascularaccess site.
 51. The method of claim 48, further comprising the step ofadvancing a blood pump across the deficient native valve.
 52. The methodof claim 51, wherein the step of advancing the catheter comprisesadvancing the catheter over the blood pump.
 53. The method of claim 51,wherein the step of advancing the blood pump comprises inserting theblood pump across the first vascular access site.
 54. The method ofclaim 51, wherein the step of advancing the blood pump comprisesinserting the blood pump across the second vascular access site.
 55. Themethod of claim 48, further comprising the steps of: advancing a stentfrom the second vascular access site to the deficient valve; deployingthe stent to substantially preclude any portion of the native valve fromobstructing blood flow.
 56. The method of claim 48, wherein the valvesupport is self-expanding.
 57. The method of claim 56, furthercomprising the step of restraining self-expansion of a portion of thevalve support to a preset diameter by at least one radial restraint 58.The method of claim 49, wherein the valve assembly further comprisesloop elements for releasably attaching the anchor to the catheter. 59.The method of claim 48, wherein the catheter comprises a filter forcatching emboli or valve fragments.
 60. The method of claim 48, whereinthe catheter comprises an over-the-wire catheter.
 61. The method ofclaim 48, wherein the catheter comprises a rapid exchange catheter. 62.A method of replacing a deficient native valve comprising the steps of:providing a prosthetic valve assembly, the assembly comprising a valve,a valve support permitting attachment thereto of the base and thecommissures of the valve, and a radial restraint controlling a diameterof at least a portion of the valve assembly; collapsing the valvesupport to fit within a distally positioned sheath on a catheter;inserting a guidewire into a vascular access site; externalizing atleast a portion of the guidewire through a second vascular access site;advancing the catheter over the guidewire to the deficient native valve;deploying the valve assembly; and withdrawing the catheter, leaving thevalve assembly to function in place of the deficient native valve. 63.The method of claim 62, wherein the step of advancing the cathetercomprises advancing the catheter to the deficient native valve from thefirst vascular access site.
 64. The method of claim 62, wherein the stepof advancing the catheter comprises advancing the catheter to thedeficient native valve from the second vascular access site.
 65. Themethod of claim 62, further comprising the step of advancing a bloodpump across the deficient native valve.
 66. The method of claim 65,wherein the step of advancing the catheter comprises advancing thecatheter over the blood pump.
 67. The method of claim 65, wherein thestep of advancing the blood pump comprises inserting the blood pumpacross the first vascular access site.
 68. The method of claim 65,wherein the step of advancing the blood pump comprises inserting theblood pump across the second vascular access site.
 69. The method ofclaim 64, further comprising the steps of: advancing a stent from thesecond vascular access site to the deficient valve; deploying the stentto substantially preclude any portion of the native valve fromobstructing blood flow.
 70. The method of claim 62, wherein the valvesupport is self-expanding.
 71. The method of claim 62, wherein the valveassembly further comprises loop elements for releasably attaching theanchor to the catheter.
 72. The method of claim 62, wherein the cathetercomprises a filter for catching emboli or valve fragments.
 73. Themethod of claim 62, wherein the catheter comprises an over-the-wirecatheter.
 74. The method of claim 62, wherein the catheter comprises arapid exchange catheter.
 75. A prosthetic valve assembly configured forendoluminal delivery to replace a deficient native valve, the valveassembly comprising a non-cylindrical valve support and at least oneanchor.
 76. A method of replacing a deficient heart valve comprising thesteps of: delivering to a target native valve site a valve prosthesiscomprising a first portion and a second portion, the first portionlimited in its expansion diameter when compared to the second portion;delivering a perfusion pump to the desired target site to pump bloodthrough the target site during application of the valve prosthesis; anddeploying the valve prosthesis while pumping blood through the targetsite.
 77. The method of claim 76, wherein the valve prosthesis furthercomprises a radial restraint.
 78. The method of claim 76, wherein thevalve prosthesis further comprises an anchor.